Patent GB-969754-A (GB)
Title: Transparent optical viewing device
IPC: C07D491/10
Filed: 1960-07-01
Abstract: The following photochromic compounds can be prepared by the methods indicated below:  IV. 1,3,3-trimethyl-61-nitro-81-allyl-spiro (21H-11-benzopyran-2,21-indoline),  V. 1,3,3-trimethyl-61-chloro-81-nitro-spiro (21H-11-benzopyran-2,21-indoline),  VI. 1,3,3-trimethyl-61,81-dibromo-spiro(21H -11-benzopyran-2,21-indoline),  VII. 1,3,3-trimethyl-61-bromo-spiro (21H-11-benzopyran-2,21-indoline),  VIII. 1,3,3-trimethyl-71-chloro-spiro (21H-11-benzopyran-2,21-indoline), IX. 1,3,3-trimethyl-61-chloro-spiro (21H -11-benzopyran-2,21-indoline),  X. 1,3,3-trimethyl-5,61-dinitro-spiro (21H -11-benzopyran-2,21-indoline),  XI. 1,3,3-trimethyl-61,81-dinitro-spiro (21H -11-benzopyran-2,21-indoline),  XII. 1,3,3-trimethyl-51-nitro-spiro (21H -11-benzopyran-2,21-indoline),  XIII. 1,3,3-trimethyl-71-nitro-spiro (21H -11-benzopyran-2,21-indoline), XIV. 1,3,3-trimethyl-71-nitro-spiro (21H -11-beta-naphthopyran, 2,21-indoline),  XVI. 3-methyl-6-nitro-8-methoxy-spiro[2H-1-benzopyran-2,21 -(21H-11-beta-naphtho-pyran)],  XVII. 1,3,3-trimethyl-81-nitro-spiro-(21H -11-benzopyran-2,21-indoline), XVIII. 1,3,3-trimethyl-51-nitro-81-methoxy-spiro -(21H-11-benzopyran-2,21-indoline),  XIX. 1,3,3-trimethyl-spiro-(21H-11-benzopyran -2,21-indoline),  XX. 1,3,3-trimethyl-51-chloro-spiro-(21H-11 -benzopyran-2,21-indoline), XXI. 1,3,3-trimethyl-81-fluoro-spiro-(21H-11 -benzopyran-2,21-indoline),  XXII. 1,3,3-trimethyl-5-nitro-61-bromo-spiro-(21H -11-benzopyran-2,21-indoline),  XXIII. 1,3,3-trimethyl-61-hydroxy-spiro-(21H -11-benzopyran-2,21-indoline), XXIV. 1,3,3-trimethyl-61-nitro-71-chloro-spiro -(21H-11-benzopyran-2,21-indoline),  XXV. 1,3,3-trimethyl-51,71-dihydroxy-spiro-(21H -11-benzopyran-2,21-indoline),  XXVI. 1,3,3-trimethyl-51,71-dimethoxy-spiro-(21H -11-benzopyran-2,21-indoline),  XXVII. 1,3,3-trimethyl-81-allyl-spiro-(21H-11 -benzopyran-2,21-indoline), XXVIII. 1,3,3-trimethyl-81-methoxy-spiro-(21H-11 -benzopyran-2,21-indoline),  XXX. 3-phenyl-71-nitro-spiro-[2H-1-benzopyran-2,21 -(21H-11-beta-naphthopyran)],  XXXI. 3-methyl-6-nitro-spiro-[2H-1-benzopyran-2,21-(21 -11-benzopyran)], XXXII. 1,3,3-trimethyl-61-methoxy-81-nitro-spiro -(21H-11-benzopyran-2,21-indoline),  XXXIII. 1,3,3-trimethyl-5-methoxy-61,81-dibromo-spiro -(21H-11-benzopyran-2,21-indoline),  XXXIV. 1,3,3-trimethyl-5-methoxy-61-nitro-spiro-(21H -11-benzopyran-2,21-indoline),  XXXV. 1,3,3-trimethyl-7-methoxy-71-chloro-spiro-(21H -11-benzopyran-2,21-indoline),  XXXVI. 1,3,3-trimethyl-7,81-dimethoxy-61-nitro-spiro -(21H-11-benzopyran-2,21-indoline),  XXXVII. 1,3,3-trimethyl-5-chloro-51,61-dinitro,81\h -methoxy-spiro-(21H-11-benzopyran-2, 21-indoline),  XXXVIII. 1,3,3-trimethyl-5-chloro-51-nitro-81-methoxy -spiro-(21H-11-benzopyran-2,21-indoline),  XXXIX. 1,3-dimethyl-3-isopropyl-61-nitro-spiro-(21H -11-benzopyran-2,21-indoline),  XLI. 71-nitro-spiro-[xantho-10,21-(21H-11 -benzo-beta-naphthopyran)], XLIV. 1,3,3,81-tetramethyl-51-hydroxymethyl-spiro -[21H-11-pyridino-([3,4-b])pyran]-2,21-indoline,  XLV. 1,3,3-trimethyl-61-nitro-81-methoxy-spiro -(21H-11-benzopyran-2,21-indoline), and XLVI. 1,3,3-trimethyl-61-nitro-spiro-(21H-11 -benzopyran-2,21-indoline). Compounds IV-XIII, XVII-XXVIII, XXXII-XXXIX, XLV and XLVI can be prepared by condensing a substituted or unsubstituted 2-methylene-1,3,3 -trimethyl indoline with a correspondingly substituted salicylaldehyde in ethanol; compound XIV by condensing 6-nitro-2-hydroxy-1-naphthaldehyde with 2-methylene-1,3,3-trimethylindoline; compound XVI by condensing 3-methoxy-5-nitro-salicylaldehyde with methyl ethyl ketone and condensing the product with 2-hydroxy-1-naphthaldehyde; compound XXX by condensing 4-nitro-salicylaldehyde with phenyl ethyl ketone and condensing the product with 2-hydroxy-1-naphthaldehyde; compound XXXI by condensing 5-nitro-salicylaldehyde with 2-hydroxystyryl ethyl ketone and treating with sodium carbonate; compound XLI by condensing 6-nitro-2-hydroxy-1-naphthaldehyde with 9-methyl-xanthenol; and compound XLIV as for compound XIV but using pyridoxal in place of 6-nitro-2-hydroxy-1-naphthaldehyde.  9-methyl-xanthenol is obtained by reacting xanthone with methyl magnesium iodide and hydrolyzing the product.  Various solvents for the compounds are referred to. Specifications 883,803, 887,902, 887,958, 889,186 and 889,586 are referred to.ALSO:A device for interposing between the eyes and incident light, e.g. a pair of spectacles, for preventing the transmission of an excess of harmful radiations to the eyes comprises in conjunction a solid transparent medium and one or a combination of photochromic spiropyran compounds in liquid, semi-solid or solid solution, which when subjected to incident light abnormally rich in U.V. radiation changes its light-absorbing properties to effect at least a reduction in the transmission of the U.V. radiation through the medium.  A coloured dyestuff can be used with the photochromic compounds.  The darkening of the device may be initiated by an activating light source preceding a burst of U.V. light, and, after darkening, an auxiliary light source or heating appliance may be used to cause reversion of the photochromic compounds to a transparent condition, if ambient normal light and temperature are <PICT:0969754/C4-C5/1> <PICT:0969754/C4-C5/2> <PICT:0969754/C4-C5/3> insufficient.  The heating may be supplied by an external application of heat or by electric heating wires embedded in the device.  In the construction shown in Fig. 2 a liquid solution 21 of photochromic material is contained in a closed transparent cell 19 of glass, quartz, cellulose nitrate, gelatin, cellulose acetate, polyvinylidene chloride or polyvinyl alcohol &c.  The outer walls of the cell may be optically flat or optically corrected.  In the construction shown in Fig. 3 two transparent sheets 23 and 24 hold between them a semi-solid solution of photochromic material.  Fig. 4 shows a transparent support sheet 27 having thereon a coating of minute transparent capsules 28 each containing a droplet of a solution of a photochromic material.  The capsules 28 can be coated with a lacquer of acrylic resin to reduce the scattering of reflected light, the resin being selected to have a transparency and refractive index close to that of the capsule walls.  Other constructions are a self-supporting continuous film containing cells filled with a solution of photochromic compounds and a transparency in which a photochromic compound or compounds are included in solid solution with a self-supporting film material. Several transparencies containing different photochromic compounds can be laminated together. Many photochromic compounds, their methods of preparation, and solvents therefor are referred to. Specifications 883,803, 887,902, 887,958, 889,186 and 889,586 are referred to.